You can try
From the rkhunter man page:
One of the checks rkhunter performs is to compare various current file properties of various commands, against those it has previously
stored. This command option causes rkhunter to update its data file of stored values with the current values.
WARNING: It is the users responsibility to ensure that the files on the system are genuine and from a reliable source. rkhunter can only
report if a file has changed, but not on what has caused the change. Hence, if a file has changed, and the --propupd command option is used,
then rkhunter will assume that the file is genuine.
But I think these warnings are nothing to worry about. I get them myself.